In the present day fluid handling technology, the sliding vane pump or compressor is widely employed as a fluid moving device as well as a fluid flow measuring device. The sliding vane pump or compressor comprises a plurality of vanes slidably engaging a plurality of radial slits included in a circular rotor cylinder that is rotatably disposed eccentrically within a circular cylindrical cavity having a fluid inlet and outlet. The sliding movements of the vanes relative to the slits are subjected to a high friction, which creates not only wear and tear on the vanes as well as the slits but also the excessive power consumption by the pumps or compressors and the high pressure drop in case of flow meters. The arrangement of the vanes slidably retained in the slits of the rotor has an inherent weakness in the structural rigidity and strength that limits the application of vane pumps or compressors to moderately low pressures.
The primary object of the present invention is to provide the flap pump-flow meter that includes all the advantages of the operating principles of the sliding vane pump-flow meter without accompanying the disadvantages of the sliding vane pump-flow meter.
Another object is to provide a positive displacement rotary pump of a high efficiency and capable of delivering a high pressure head.
A further object is to provide a positive displacement rotary pump of a compact and light weight construction.
Yet another object is to provide a positive displacement rotary flow meter of a high sensitivity and great accuracy that is applicable to high pressure fluid flow.
Yet a further object is to provide a positive displacement rotary flow meter of a compact construction including simple elements.
These and other objects of the present invention will become clear as the description thereof proceeds.